In recent years the market has demanded storage systems with low cost, high performance, and high function. Storage systems can normally be broadly divided into a controller and a group of physical storage devices, and one way to obtain high performance and high function from a storage system is to make the controller have high performance and high function. Specifically, the method of increasing the frequency of the processor to increase the performance of the LSI (large scale integration) that transmits data within the controller, and so on, can be considered.
However, if the controller has high performance and high function, normally the cost of the storage system itself is increased. Therefore, instead of making the controller high performance and high function, it is considered that it is necessary to make the processes within the storage system more efficient.
Technology for making the processes within the storage system more efficient is disclosed in, for example, Patent Literatures 1 and 2. According to Patent Literature 1, a first type of path suitable for high response and a second type of path suitable for high throughput are provided between a first controller and a second controller, and these two types of paths are used accordingly. According to Patent Literature 2, when from among a first type of resource and a second type of resource, the load on one type of resource is high and the load on the other type of resource is within the capacity, processes are executed so that the load on the other type of resource increases.